1. Field of the Invention
The invention relates to an oil bailer apparatus for use in bailing oil from an oil well as well as removing natural gas, wherein a bailer tube is lowered to collect the fluid and raised above ground for the depositing of the fluids into a reservoir.
2. Description of Related Art
Oil bailers are known in the art. However, previous methods of extracting oil, in particular, the bailers and controls used with such bailers fail to differentiate between oil and water in a given well. The problem of non-differentiating between water and oil is especially experienced in low producing wells.
Known related art includes the solid state control system for the oil bailer depicted in U.S. Pat. No. 4,516,911 to Senghaas et al., the oil bailer depicted in U.S. Pat. No. 4,368,909 to Alexander, Jr., and the automated bailer depicted in U.S. Pat. No. 4,037,662 to Bowling.
None of the devices in the above references solve the problem of differentiating between water and oil, especially in low producing wells, and at the same time, address the recovery of natural gas from the oil pumping operation.
It is therefore the intention of this invention to provide an improved oil bailing system, which differentiates between oil and water in a given well, removes only oil, capable of operating on 5,000 foot wells and operates at the removal rate of 25-35 barrels per day. The invention can differentiate between water and oil by the incorporation in the system design of a programmable logic control (PLC) to operate the mechanical system portion of the apparatus, and to provide means for accessing and collecting data of the operation of the equipment including system errors. This will be used to gather and record daily gas and oil production and then transfer all data to a central terminal PC by way of the internet.
The invention which is an apparatus and system control for the removal of fluids and gas from a well includes means for removing fluids from a well casing, and the fluids being substantially oil and water.
The means for removing fluids from the well casing is coupled directly to an upper end of the well casing and further includes a bailer tube sized to allow an up and down travel of the bailer tube inside the well casing and inside a bailer tube housing assembly vertically aligned with the well casing. The direct coupling may be made by a number of ways known in the art such as a flanged pipe connection or preferably a union connection. The bailer tube housing assembly has an actuated 3-way valve means proximate a lower end of the bailer tube housing assembly for selectively opening the bailer tube housing assembly when allowing the bailer tube to travel into the well casing and for closing the bailer tube housing assembly after the bailer tube has traveled up into the bailer tube housing assembly and for directing a captured column of oil to a temporary storage tank.
Also included is pulley means proximate an upper end of and above the bailer tube housing assembly over which a cable wire attached to an upper end of the bailer tube is run. An opposite end of the cable wire is attached to driven winch means for pulling the bailer tube out of the well casing and for lowering the bailer tube into the well casing. A lower end of the bailer tube has a bailer valve for selectively capturing the column of oil inside the well casing when said bailer tube is lowered therein, and for discharging said captured column of oil into the temporary storage tank when the bailer tube is raised out of the well casing. The bailer valve is typically a two-way direct current (DC) valve.
The bailer valve is in electrical operative communication with a programmable logic controller (PLC) means for monitoring, operating and controlling the apparatus and for translating readable information to obtain and record operational parameters. The PLC means is typically an electrical enclosure housing with various processing capabilities which includes a micro-processing unit typical of computers, gauges for monitoring various desired operating parameters such as flow rates of oil and gases, oil level in the temporary storage tank, pressures, bailer tube travel speeds, etc., actuator switches for activating and controlling the winch and pumping means to empty the temporary storage tank, among several other necessary or desired functions.
The lower end of the bailer tube further includes at least one oil and water sensing means, that is, at least one oil sensor and at least one water sensor, for differentiating between the water and oil inside the well casing as the bailer tube descends therein, the oil and water sensing means facilitating the defining of a top of the water and a bottom of a well casing column of oil. The cable wire is typically a multiple conductor cable wire, which is in electrical communication between the bailer valve and the driven winch means.
The cable wire is also electrically and operatively connected to the programmable logic controller means. The programmable logic controller means calculates an optimum depth required for removal of oil without water from the well casing and once correctly positioned, the bailer valve is closed thereby capturing oil inside said bailer tube and the bailer tube is elevated so that the bailer valve is inside the bailer housing assembly and above the actuated 3-way valve means at which location, the actuated 3-way valve means is closed after which the bailer valve is opened and the captured oil in the bailer tube is discharged into the temporary storage tank. The actuated 3-way valve means, the driven winch means, the oil and water sensor means are each in electrical and operative communication with the programmable logic controller means. The programmable logic controller means controls and monitors a speed of the bailer tube at each location of the bailer tube inside the well casing as the bailer tube is being lowered into and elevated out of the well casing.
The invention further includes natural gas recovery means for recovering a natural gas exhausting from the well casing. The natural gas recovery means comprises a gas and oil separator means, which directs the natural gas exiting the well casing from a location below the actuated 3-way valve means, and means for draining a condensate and means for directing a separated gas to gas distribution means.
The oil and water sensor means is typically a ground probe switch which is activated when a conductive path between a terminal of said ground probe switch is established as the terminal contacts the water under the oil in the well casing thereby defining the top of the water and the bottom of the well casing column of oil.
The driven winch means preferably further comprises encoder means in electrical communication with the programmable logic controller means for converting a rotation of the winch means into a linear motion to determine a speed of the bailer tube traveling inside the well casing and a location within said well casing.
The temporary storage means comprises means for monitoring the level of captured oil in the temporary storage tank, and actuation means operatively connected to pumping means for pumping the captured oil from the temporary storage tank to a predetermined storage location.
The actuated 3-way valve means is preferably one of a slide gate valve and a ball valve.
The natural gas recovery means further comprises means for monitoring one of a flow rate of natural gas exhausting from the well casing, a volumetric quantity of natural gas exhausting from the well casing, and a combination thereof. A corresponding natural gas recovery means data from the means for monitoring one of the flow rate of natural gas exhausting from the well casing, the volumetric quantity of natural gas exhausting from the well casing, and the combination thereof is transmitted to the programmable logic controller means.
Support and guide means at the upper end of the bailer housing assembly for supporting and guiding the wire cable are also included. The support and guide means comprises a stuffing box and sheave assembly including at least one wire cable line wiper and at least one hydraulic greasing port for greasing said wire cable. Typically, the stuffing box and sheave assembly includes a first hydraulic greasing port in overlying relationship to a first line wiper, a second hydraulic greasing port in underlying relationship to the first line wiper and a second line wiper in underlying relationship to the second hydraulic greasing port.
The invention further comprises a proximity sensor switch located proximate the upper end of the bailer housing assembly. The proximity sensor switch is in electrical communication with the programmable logic controller means and being means for stopping the bailer tube being raised from the well casing. A back up proximity sensor switch located in a predetermined spaced apart relationship with the proximity sensor switch, typically about 4-8 inches above the proximity sensor switch, is included and acts as means for stopping the bailer tube should the proximity sensor switch fail. This switch is also in electrical communication with the programmable logic controller means.
The programmable logic controller means further monitors a top of the oil column location within the well casing as well as a bottom location of the oil column within the well casing, the bottom location corresponding to a location of the top of the water column within the well casing. The optimum depth in the well casing of the lower end of the bailer tube for capturing the column of oil without water is an intermediate location between the location of the top of the oil column and above the location of the bottom of the oil column.
The programmable logic controller means performs an operational logging sequence during which the programmable logic controller means operationally opens the bailer valve and the actuated 3-way valve means, starts the lowering of the bailer tube into the well casing accelerating to a predetermine adjustable travel speed, allows the bailer tube to descend to a preset logging depth above the location of the top of the oil column within the well casing, decreases the adjustable travel speed so that the lower end of the bailer tube enters into the oil column at which point the oil sensor means identifies a depth of the top of the oil column, the lower end of the bailer tube continues to descend until the water sensor means identifies a depth of the top of the water in the well casing, transmits data reflective of the identification of the depth of the top of the oil and water to the programmable logic controller means which recalculates desired operational parameters including a new logging depth, optimum depth and bailer tube travel speed, closes the bailer valve, starts elevating the bailer tube through the well casing until the bailer tube enters the bailer tube housing assembly, stops the bailer tube when the lower end of the bailer tube is above the actuated 3-way valve means, closes the actuated 3-way valve means, opens the bailer valve for a predetermined top dwell time thereby discharging the captured oil in the bailer tube inside the temporary storage tank, closes the bailer valve after the captured oil has been discharged into the temporary storage tank, and repeats the above operational logging sequence as desired.
The programmable logic controller means also performs a balanced oil production operational sequence during which the programmable logic controller means operationally opens the bailer valve and the actuated 3-way valve means, starts the lowering of the bailer tube into the well casing accelerating to a predetermine adjustable travel speed, allows the bailer tube to descend to a pre-set logging depth above the location of the top of the oil column within the well casing, decreases the adjustable travel speed so that the second end of the bailer tube enters into the oil column at which point the oil sensor means identifies a depth of the top of the oil column, the lower end of the bailer tube continues to descend into the oil column and stops at the optimum depth at which point the bailer valve is closed after a predetermined preset dwell time to capture oil, transmits data reflective of the identification of the depth of the top of the oil and optimum depth to the programmable logic controller means which continually calculates and monitors desired operational parameters including the logging depth, optimum depth and bailer tube travel speed, starts elevating the bailer tube through the well casing until the upper end of the bailer tube enters the bailer tube housing assembly, stops the bailer tube when the lower end of the bailer tube is above the actuated 3-way valve means, closes the actuated 3-way valve means, opens the bailer valve for a predetermined top dwell time thereby discharging the captured oil in the bailer tube inside the temporary storage tank, closes the bailer valve after the captured oil has been discharged into the temporary storage tank, and repeats the above balanced oil production operational sequence as desired.
The programmable logic controller means further monitors an accumulated level of oil in the temporary storage tank, monitors gaseous pressure, monitors oil pressure in the well casing and temporary storage tank using corresponding pressure sensor means, and monitors a tension in the cable wire.
The invention further comprises a field communicator, which is operatively in communication with the programmable logic controller means. The field communicator is operatively in communication with a data base server, the data base server for storing, organizing and polling data outputted from the programmable logic controller means, for users to change operating parameters of the programmable logic controller means, for providing historical data and performing diagnostics, and for providing data collection, reporting, analysis and visualization displays. The data base server is accessible by a user through a website. Another embodiment is the inclusion of a paging system in operative communication with the programmable logic controller means, the paging system for communicating pre-set alarms and messages between a field service department and the programmable logic controller means.
The inventive method comprises the steps of providing an apparatus and system control for the removal of oil and gas from a well as described above; conducting a first sequence logging process during which the programmable logic controller means operationally opens the bailer valve and the actuated 3-way valve means, starts the lowering of the bailer tube into the well casing accelerating to a predetermine adjustable travel speed, allows the bailer tube to descend to a pre-set logging depth above the location of the top of the oil column within the well casing, decreases the adjustable travel speed so that the lower end of the bailer tube enters into the oil column at which point the oil sensor means identifies a depth of the top of the oil column, the second end of the bailer tube continues to descend until the water sensor means identifies a depth of the top of the water in the well casing, transmits data reflective of the identification of the depth of the top of the oil and water to the programmable logic controller means which recalculates desired operational parameters including a new logging depth, optimum depth and bailer tube travel speed, closes the bailer valve, starts elevating the bailer tube through the well casing until the bailer tube enters the bailer tube housing assembly, stops the bailer tube when the lower end of the bailer tube is above the actuated 3-way valve means, closes the actuated 3-way valve means, opens the bailer valve for a predetermined top dwell time thereby discharging the captured oil in the bailer tube inside the temporary storage tank, closes the bailer valve after the captured oil has been discharged into the temporary storage tank, and repeats the above operational logging sequence as desired; and performing a balanced oil production operational sequence during which the programmable logic controller means operationally opens the bailer valve and the actuated 3-way valve means, starts the lowering of the bailer tube into the well casing accelerating to the predetermine adjustable travel speed, allows the bailer tube to descend to the pre-set logging depth above the location of the top of the oil column within the well casing, decreases the adjustable travel speed so that the lower end of the bailer tube enters into the oil column at which point the oil sensor means identifies the depth of the top of the oil column, the lower end of the bailer tube continues to descend into the oil column and stops at the optimum depth at which point the bailer valve is closed after the predetermined preset dwell time to capture oil, transmits the data reflective of the identification of the depth of the top of the oil and optimum depth to the programmable logic controller means which continually calculates and monitors desired operational parameters including the logging depth, optimum depth and bailer tube travel speed, starts elevating the bailer tube through the well casing until the first end of the bailer tube enters the temporary storage tank, stops the bailer tube when the lower end of the bailer tube is above the actuated 3-way valve means, closes the actuated 3-way valve means, opens the bailer valve for a predetermined top dwell time thereby discharging the captured oil in the bailer tube inside the temporary storage tank, closes the bailer valve after the captured oil has been discharged into the temporary storage tank, and repeats the above balanced oil production operational sequence until a change in depth is noted such as to require re-initiation of the logging process.
The programmable logic controller means can be programmed to cycle through the first sequence logging process at predetermined time intervals. The programmable logic controller means monitors the rate that the oil column is decreasing or increasing and makes necessary adjustments to slow down or speed up a normal running sequence. The normal running sequence starts out with the travel speed at an optimum operating speed and as a rate of the oil column is decreasing, the programmable logic controller means compares this rate with a current rate of speed of the bailer tube and slows the travel speed of the bailer tube slightly with every cycle, and while monitoring the rate of decrease of the oil column, the programmable logic controller means continuously makes small adjustments until the oil column stops decreasing in size and maintains a steady constant size. The programmable logic controller means continues to run at the travel speed of the bailer tube while continuing to monitor the size of the oil column, and continues to make adjustments in order to maintain a balanced sized oil column.
In another embodiment of the invention, the PLC means for one or more field sites is operatively connected with one or more Field Communicator PCs, each including a dial up modem, ISDN connector and an FTP router, which in turn communicates with a data base server PC. This server is accessible through a website in which data collection, reporting, analysis and visualization displays can be viewed by a customer base. In addition, each PLC means is operatively in communication with a paging system, which outputs data to a field service department.